
	class Thread_2252 {
		// 计数器private static volatile int COUNTER = 0;
		// 定义一个单独的锁对象private static Object lock = new Object();
		private static Object lock = new Object();
		private static volatile int COUNTER = 0;

		public static void main(String[] args) {
			// 创建三个线程，并指定线程名，每个线程名分别用A,B,C表示
			Thread t1 = new Thread(() -> {
				// 循环10次
				for (int i = 0; i < 10; i++) {
					// 执行的代码加锁
					synchronized (lock) {
						while (COUNTER % 3 != 0) {
							// 每次唤醒后都重新判断是否满足条件// 每条线程判断的条件不一样，注意线程t1,t2while (COUNTER % 3 != 0) {
							try {
								// 不满足输出条件时，主动等待并释放锁
								lock.wait();
							} catch (InterruptedException e) {
								e.printStackTrace();
							}
						}
						// 满足输出条件，打印线程名，每条线程打印的内容不同System.out.print(Thread.currentThread().getName());
						// 累加计数
						System.out.print(Thread.currentThread().getName());
						COUNTER++;
						// 唤醒其他线程
						lock.notifyAll();
					}
				}
			}, "A");
			Thread t2 = new Thread(() -> {
				for (int i = 0; i < 10; i++) {
					synchronized (lock) {
						while (COUNTER % 3 != 1) {
							try {
								lock.wait();
							} catch (InterruptedException e) {
								e.printStackTrace();
							}
						}
						System.out.print(Thread.currentThread().getName());
						COUNTER++;
						lock.notifyAll();
					}
				}
			}, "B");
			Thread t3 = new Thread(() -> {
				for (int i = 0; i < 10; i++) {
					synchronized (lock) {
						while (COUNTER % 3 != 2) {
							try {
								lock.wait();
							} catch (InterruptedException e) {
								e.printStackTrace();
							}
						}
						System.out.println(Thread.currentThread().getName());
						COUNTER++;
						lock.notifyAll();
					}
				}
			}, "C");
			// 启动线程
			t1.start();
			t2.start();
			t3.start();
		}
	}






//第二个版本参考答案: 使用三个锁, 分别控制.
//
//
//
//public class Demo {
//	private static Object locker1 = new Object();
//	private static Object locker2 = new Object();
//	private static Object locker3 = new Object();
//
//	public static void main(String[] args) throws InterruptedException {
//		Thread t1 = new Thread(() -> {
//			try {
//				for (int i = 0; i < 10; i++) {
//					synchronized (locker1) {
//						locker1.wait();
//					}
//					System.out.print("A");
//					synchronized (locker2) {
//						locker2.notify();
//					}
//				}
//			} catch (InterruptedException e) {
//				e.printStackTrace();
//			}
//		});
//
//		Thread t2 = new Thread(() -> {
//			try {
//				for (int i = 0; i < 10; i++) {
//					synchronized (locker2) {
//						locker2.wait();
//					}
//					System.out.print("B");
//					synchronized (locker3) {
//						locker3.notify();
//					}
//				}
//			} catch (InterruptedException e) {
//				e.printStackTrace();
//			}
//		});
//
//		Thread t3 = new Thread(() -> {
//			try {
//				for (int i = 0; i < 10; i++) {
//					synchronized (locker3) {
//						locker3.wait();
//					}
//					System.out.println("C");
//					synchronized (locker1) {
//						locker1.notify();
//					}
//				}
//			} catch (InterruptedException e) {
//				e.printStackTrace();
//			}
//		});
//		t1.start();
//		t2.start();
//		t3.start();
//
//		Thread.sleep(1000);
//
//		// 从线程 t1 启动
//		synchronized (locker1) {
//			locker1.notify();
//		}
//	}
//}
//}
